When tightening a fastener such as a nut or bolt, the type of tool that is often utilized is a tool including a ratcheting mechanism. The ratcheting mechanism enables the tool to be rotated in only a single direction, such that the tool can be easily manipulated by an individual to quickly and effectively tighten the nut or bolt the desired amount.
However, in certain applications the degree to which the fastener is tightened must be closely controlled in order to avoid any over-tightening. One particularly relevant application in which this type of control is required is in the medical field where screws and other types of fasteners are inserted directly into an individual to speed the healing of a particular injured body part of an individual, e.g. a broken bone. By precisely tightening the fasteners, the physician can provide the most effective treatment for the individual without causing any further damage to the individual or inadvertently slowing the healing process.
However, while the ratchet tools currently used in the medical field and in other areas are capable of tightening screws and other fasteners, any prior art ratchet tools suffer from a number of problems that prevent the tools from being utilized most efficiently. One problem is that often times it is difficult for an individual using the ratchet tool to determine when the fastener is tightened to the proper amount based as a result of the construction of the ratchet tool. More specifically, most ratchet tools have a “sloppy feel” as a result of their design, which prevents an individual from feeling the resistance exerted on the tool by the fastener in order to accurately determine when the fastener is properly tightened. Also, when external attachments or shaft couplers are connected to the tool, the loss of feel when utilizing the tool is compounded.
Further, another problem associated with prior art ratchet tools arises due to the positioning of the central gear within the tool. More particularly, when the tool has been used for a certain amount of time, the central gear in the ratcheting mechanism tends to move out of concentricity with the handle of the tool, such that the gear “runs out” with regard to the handle, thereby limiting the effectiveness of the tool.
Finally, another shortcoming of the prior art ratchet tools arises because tools utilized in medical scenarios must be sterilized between uses. Based on the open construction of prior art tools, the use of cleaning solutions to sterilize tools of this type often times cannot adequately clean the internal portions of the tool such that the tool retains dirt or other debris, including residual cleaning fluid, within the interior of the mechanism which can significantly affect the ability operation of the tool to be used.
Therefore, to remedy these problems it is desirable to develop a ratchet tool for use in a variety of situations where the tool has a ratchet mechanism construction that provides adequate feel of the resistance of the fastener to the individual utilizing the tool through the tool. The improved ratchet tool construction should also effectively prevent any run out of the central gear with respect to the tool, while also effectively sealing off the interior of the tool from the exterior of the tool such that no fluid, gas or debris can get into the tool and affect the operation and/or usefulness of the tool.